244 MOEPHOLOGY AND EVOLUTION
The deep epigastric artery in the Chimpanzee arises from the external iliac or femoral artery. It runs up in the sheath of the rectus muscle, but it does not anastomose with the superficial epigastric branch of the internal mammary artery. In rare cases it arises from the femoral artery in Man. The obturator artery is similar in the Apes and in Man.
The circumflex arteries in the Chimpanzee differ from those in Man. The mesial femoral circumflex artery runs down over the head of the femur under the adductor muscles and supplies the psoas, obturator internus, adductor magnus and capsule of the hip-joint. It then passes to the back of the thigh and sends branches to the adductor magnus, gluteus maximus, quadratus femoris and biceps. It also gives off an arteria comes nervi ischiadici. The lateral femoral circumflex artery divides into ascending, transverse and descending branches, each of which supplies muscles and the hip-joint. The ascending branch supplies the glutei and rectus femoris, the transverse branch supplies the gluteus maximus and vastus externus, and the descending branch supplies the rectus femoris, vastus externus and crureus. Eisler (442) points out that the vessels differ on Koth sides in the Gorilla; the circumflex arteries may arise from the profunda femoris; the mesial artery may give off the obturator artery, and the lateral artery may give off the superficial epigastric and external pudendal arteries.
The profitnda femoris gives off two perforating arteries in the Gorilla, but there are no true perforating arteries in the Chimpanzee.
The popliteal artery in the Chimpanzee gives off branches to the gastrocnemius, an articular artery to the